The Playstation Vita's been out in Japan since December so this guy's got quite the leg up on the competition, especially if you're a player of Ultimate Marvel vs. Capcom 3 on the handheld.
Apparently he couldn't stand the native controls and decided he was going to do something about it, then hacked and fitted the system to an arcade stick. Why someone would do this is beyond me considering none of the top tier players within the fighting community would even come 15 feet within a fighter on the Vita.
So while this may be a pretty nifty hack, in the end you may be the only guy on the block, or in the world, with the ability to get lightning fast input speed, it doesn't really matter when those who you're playing against aren't really taking the game as serious as it can be taken competitively.
Also, doesn't that take away from the platform's on-the-go mentality? Okay, okay I'm being a little harsh on the dude. He was probably just doing this as a hobby project anyway but I don't see any real world applications here, do you?